1. Always treat every firearm as though it is loaded.
2. Always keep the muzzle pointed in a safe direction.
3. Keep your finger outside the trigger guard until ready to shoot.
4. Always be sure of your target and what is in front of it and behind it.

even by NRA:

1. The Gun Is Always Loaded
2. Never Point The Gun At Something You Are Not Prepared To Destroy
3. Always Be Sure Of Your Target And What Is Behind It
4. Keep Your Finger Off The Trigger Until

aiming at a game animal that is a hunting target is not a violation of any rule or principle of gun safety... the troll just got his bait bit. Gloating about it adds a touch of class.